Systematic Analysis of Whole Exome Sequencing Determines RET G691S Polymorphism as Germline Variant in Melanoma

Abstract The RET proto-oncogene encodes a receptor tyrosine kinase that is activated by glial cell derived neutrotrophic factor (GDNF). Previous studies have found that a single nucleotide polymorphism (SNP), RETp (G691S), in the juxtamembrane domain enhances the signaling pathway and promotes tumor growth by GDNF in pancreatic and thyroid cancer in addition to melanoma. It is uncertain however whether this SNP is a germline variant or somatic mutation. A prior study reported that the RETp variant was a germline SNP in desmoplastic and non-desmoplastic melanomas. In the present study, we examined both melanoma tissue samples and matching peripheral blood DNA to determine if RETp was 1) a germline or somatic variant, 2) more frequent in certain melanoma subtypes, and 3) frequency in brain metastasis. We examined the peripheral blood of 197 melanoma patients whom had at least one matched tumor, and 42 patients with brain metastasis. RETp was present as a germline SNP in 33% of patients. There were no significant differences in RETp frequency among the different melanoma subtypes, and RETp was not correlated with brain metastasis

Machine learning approaches to enhance diagnosis and staging of patients with MASLD using routinely available clinical information

Aims: Metabolic dysfunction Associated Steatotic Liver Disease (MASLD) outcomes such as MASH (metabolic dysfunction associated steatohepatitis), fibrosis and cirrhosis are ordinarily determined by resource-intensive and invasive biopsies. We aim to show that routine clinical tests offer sufficient information to predict these endpoints. Methods: Using the LITMUS Metacohort derived from the European NAFLD Registry, the largest MASLD dataset in Europe, we create three combinations of features which vary in degree of procurement including a 19-variable feature set that are attained through a routine clinical appointment or blood test. This data was used to train predictive models using supervised machine learning (ML) algorithm XGBoost, alongside missing imputation technique MICE and class balancing algorithm SMOTE. Shapley Additive exPlanations (SHAP) were added to determine relative importance for each clinical variable. Results: Analysing nine biopsy-derived MASLD outcomes of cohort size ranging between 5385 and 6673 subjects, we were able to predict individuals at training set AUCs ranging from 0.719-0.994, including classifying individuals who are At-Risk MASH at an AUC = 0.899. Using two further feature combinations of 26-variables and 35-variables, which included composite scores known to be good indicators for MASLD endpoints and advanced specialist tests, we found predictive performance did not sufficiently improve. We are also able to present local and global explanations for each ML model, offering clinicians interpretability without the expense of worsening predictive performance. Conclusions: This study developed a series of ML models of accuracy ranging from 71.9—99.4% using only easily extractable and readily available information in predicting MASLD outcomes which are usually determined through highly invasive means

Systematic Analysis of Whole Exome Sequencing Determines RET G691S Polymorphism as Germline Variant in Melanoma

The RET proto-oncogene encodes a receptor tyrosine kinase that is activated by glial cell derived neutrotrophic factor (GDNF). Previous studies have found that a single nucleotide polymorphism (SNP), RETp (G691S), in the juxtamembrane domain enhances the signaling pathway and promotes tumor growth by GDNF in pancreatic and thyroid cancer in addition to melanoma. It is uncertain however whether this SNP is a germline variant or somatic mutation. A prior study reported that the RETp variant was a germline SNP in desmoplastic and non-desmoplastic melanomas. In the present study, we examined both melanoma tissue samples and matching peripheral blood DNA to determine if RETp was 1) a germline or somatic variant, 2) more frequent in certain melanoma subtypes, and 3) frequency in brain metastasis. We examined the peripheral blood of 197 melanoma patients whom had at least one matched tumor, and 42 patients with brain metastasis. RETp was present as a germline SNP in 33% of patients. There were no significant differences in RETp frequency among the different melanoma subtypes, and RETp was not correlated with brain metastasis

Machine learning approaches to enhance diagnosis and staging of patients with MASLD using routinely available clinical information

\ua9 2024 McTeer et al.Aims Metabolic dysfunction Associated Steatotic Liver Disease (MASLD) outcomes such as MASH (metabolic dysfunction associated steatohepatitis), fibrosis and cirrhosis are ordinarily determined by resource-intensive and invasive biopsies. We aim to show that routine clinical tests offer sufficient information to predict these endpoints. Methods Using the LITMUS Metacohort derived from the European NAFLD Registry, the largest MASLD dataset in Europe, we create three combinations of features which vary in degree of procurement including a 19-variable feature set that are attained through a routine clinical appointment or blood test. This data was used to train predictive models using supervised machine learning (ML) algorithm XGBoost, alongside missing imputation technique MICE and class balancing algorithm SMOTE. Shapley Additive exPlanations (SHAP) were added to determine relative importance for each clinical variable. Results Analysing nine biopsy-derived MASLD outcomes of cohort size ranging between 5385 and 6673 subjects, we were able to predict individuals at training set AUCs ranging from 0.719-0.994, including classifying individuals who are At-Risk MASH at an AUC = 0.899. Using two further feature combinations of 26-variables and 35-variables, which included composite scores known to be good indicators for MASLD endpoints and advanced specialist tests, we found predictive performance did not sufficiently improve. We are also able to present local and global explanations for each ML model, offering clinicians interpretability without the expense of worsening predictive performance. Conclusions This study developed a series of ML models of accuracy ranging from 71.9—99.4% using only easily extractable and readily available information in predicting MASLD outcomes which are usually determined through highly invasive means

Complexity and nationalism

Classic theories of nationalism, whether modernist or ethnosymbolist, emphasise the role of elites and spread of a common imagined community from centre to periphery. Recent work across a range of disciplines challenges this account by stressing the role of horizontal, peer-to-peer, dynamics alongside top-down flows. Complexity theory, which has recently been applied to the social sciences, expands our understanding of horizontal national dynamics. It draws together contemporary critiques, suggesting that researchers focus on the network properties of nations and nationalism. It stresses that order may emerge from chaos, hence 'national' behaviour may appear without an imagined community. Treating nations like complex systems whose form emerges from below should focus research on four central aspects of complexity: emergence, feedback loops, tipping points and distributed knowledge, or 'the wisdom of crowds'. This illuminates how national identity can be reproduced by popular activities rather than the state; why nationalist ideas may gestate in small circles for long periods, then suddenly spread; why secession is often contagious; and why wide local variation in the content of national identity strengthens rather than weakens the nation’s power to mobilise

Body Mass Index and the Prevalence of Hypertension and Dyslipidemia

Objective: To describe and evaluate relationships between body mass index (BMI) and blood pressure, cholesterol, high‐density lipoprotein‐cholesterol (HDL‐C), and hypertension and dyslipidemia. Research Methods and Procedures: A national survey of adults in the United States that included measurement of height, weight, blood pressure, and lipids (National Health and Nutrition Examination Survey III 1988–1994). Crude age‐adjusted, age‐specific means and proportions, and multivariate odds ratios that quantify the association between hypertension or dyslipidemia and BMI, controlling for race/ethnicity, education, and smoking habits are presented. Results: More than one‐half of the adult population is overweight (BMI of 25 to 29.9) or obese (BMI of ≥30). The prevalence of high blood pressure and mean levels of systolic and diastolic blood pressure increased as BMI increased at ages younger than 60 years. The prevalence of high blood cholesterol and mean levels of cholesterol were higher at BMI levels over 25 rather than below 25 but did not increase consistently with increasing BMI above 25. Rates of low HDL‐C increased and mean levels of HDL‐C decreased as levels of BMI increased. The associations of BMI with high blood pressure and abnormal lipids were statistically significant after controlling for age, race or ethnicity, education, and smoking; odds ratios were highest at ages 20 to 39 but most trends were apparent at older ages. Within BMI categories, hypertension was more prevalent and HDL‐C levels were higher in black than white or Mexican American men and women. Discussion: These data quantify the strong associations of BMI with hypertension and abnormal lipids. They are consistent with the national emphasis on prevention and control of overweight and obesity and indicate that blood pressure and cholesterol measurement and control are especially important for overweight and obese people.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93762/1/oby.2000.79.pd

Towards a Clinically Relevant Lentiviral Transduction Protocol for Primary Human CD34+ Hematopoietic Stem/Progenitor Cells

Background: Hematopoietic stem cells (HSC), in particular mobilized peripheral blood stem cells, represent an attractive target for cell and gene therapy. Efficient gene delivery into these target cells without compromising self-renewal and multipotency is crucial for the success of gene therapy. We investigated factors involved in the ex vivo transduction of CD34 + HSCs in order to develop a clinically relevant transduction protocol for gene delivery. Specifically sought was a protocol that allows for efficient transduction with minimal ex vivo manipulation without serum or other reagents of animal origin. Methodology/Principal Findings: Using commercially available G-CSF mobilized peripheral blood (PB) CD34 + cells as the most clinically relevant target, we systematically examined factors including the use of serum, cytokine combinations, prestimulation time, multiplicity of infection (MOI), transduction duration and the use of spinoculation and/or retronectin. A self-inactivating lentiviral vector (SIN-LV) carrying enhanced green fluorescent protein (GFP) was used as the gene delivery vehicle. HSCs were monitored for transduction efficiency, surface marker expression and cellular function. We were able to demonstrate that efficient gene transduction can be achieved with minimal ex vivo manipulation while maintaining the cellular function of transduced HSCs without serum or other reagents of animal origin. Conclusions/Significance: This study helps to better define factors relevant towards developing a standard clinical protocol for the delivery of SIN-LV into CD34 + cells

agr-Mediated Dispersal of Staphylococcus aureus Biofilms

The agr quorum-sensing system of Staphylococcus aureus modulates the expression of virulence factors in response to autoinducing peptides (AIPs). Recent studies have suggested a role for the agr system in S. aureus biofilm development, as agr mutants exhibit a high propensity to form biofilms, and cells dispersing from a biofilm have been observed displaying an active agr system. Here, we report that repression of agr is necessary to form a biofilm and that reactivation of agr in established biofilms through AIP addition or glucose depletion triggers detachment. Inhibitory AIP molecules did not induce detachment and an agr mutant was non-responsive, indicating a dependence on a functional, active agr system for dispersal. Biofilm detachment occurred in multiple S. aureus strains possessing divergent agr systems, suggesting it is a general S. aureus phenomenon. Importantly, detachment also restored sensitivity of the dispersed cells to the antibiotic rifampicin. Proteinase K inhibited biofilm formation and dispersed established biofilms, suggesting agr-mediated detachment occurred in an ica-independent manner. Consistent with a protease-mediated mechanism, increased levels of serine proteases were detected in detaching biofilm effluents, and the serine protease inhibitor PMSF reduced the degree of agr-mediated detachment. Through genetic analysis, a double mutant in the agr-regulated Aur metalloprotease and the SplABCDEF serine proteases displayed minimal extracellular protease activity, improved biofilm formation, and a strongly attenuated detachment phenotype. These findings indicate that induction of the agr system in established S. aureus biofilms detaches cells and demonstrate that the dispersal mechanism requires extracellular protease activity

Performance of non-invasive tests and histology for the prediction of clinical outcomes in patients with non-alcoholic fatty liver disease: an individual participant data meta-analysis

BackgroundHistologically assessed liver fibrosis stage has prognostic significance in patients with non-alcoholic fatty liver disease (NAFLD) and is accepted as a surrogate endpoint in clinical trials for non-cirrhotic NAFLD. Our aim was to compare the prognostic performance of non-invasive tests with liver histology in patients with NAFLD.MethodsThis was an individual participant data meta-analysis of the prognostic performance of histologically assessed fibrosis stage (F0–4), liver stiffness measured by vibration-controlled transient elastography (LSM-VCTE), fibrosis-4 index (FIB-4), and NAFLD fibrosis score (NFS) in patients with NAFLD. The literature was searched for a previously published systematic review on the diagnostic accuracy of imaging and simple non-invasive tests and updated to Jan 12, 2022 for this study. Studies were identified through PubMed/MEDLINE, EMBASE, and CENTRAL, and authors were contacted for individual participant data, including outcome data, with a minimum of 12 months of follow-up. The primary outcome was a composite endpoint of all-cause mortality, hepatocellular carcinoma, liver transplantation, or cirrhosis complications (ie, ascites, variceal bleeding, hepatic encephalopathy, or progression to a MELD score ≥15). We calculated aggregated survival curves for trichotomised groups and compared them using stratified log-rank tests (histology: F0–2 vs F3 vs F4; LSM: 2·67; NFS: 0·676), calculated areas under the time-dependent receiver operating characteristic curves (tAUC), and performed Cox proportional-hazards regression to adjust for confounding. This study was registered with PROSPERO, CRD42022312226.FindingsOf 65 eligible studies, we included data on 2518 patients with biopsy-proven NAFLD from 25 studies (1126 [44·7%] were female, median age was 54 years [IQR 44–63), and 1161 [46·1%] had type 2 diabetes). After a median follow-up of 57 months [IQR 33–91], the composite endpoint was observed in 145 (5·8%) patients. Stratified log-rank tests showed significant differences between the trichotomised patient groups (p<0·0001 for all comparisons). The tAUC at 5 years were 0·72 (95% CI 0·62–0·81) for histology, 0·76 (0·70–0·83) for LSM-VCTE, 0·74 (0·64–0·82) for FIB-4, and 0·70 (0·63–0·80) for NFS. All index tests were significant predictors of the primary outcome after adjustment for confounders in the Cox regression.InterpretationSimple non-invasive tests performed as well as histologically assessed fibrosis in predicting clinical outcomes in patients with NAFLD and could be considered as alternatives to liver biopsy in some cases